// TonEvent = procedure of object;    //定义事件过程类型后加面加 of object
  Tcls = class
  private
    FonEvent: TNotifyEvent;
  public
    procedure show(sender: TObject);
    property onEvent: TNotifyEvent read FonEvent write FonEvent;
    constructor create;
  end;
var
  Form1: TForm1;

implementation

{$R *.dfm}

constructor Tcls.create;
begin
  FonEvent := show;
end;

procedure Tcls.show;
begin
  ShowMessage('触发事件');
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  Tc: Tcls;
begin
  Tc := Tcls.Create;
  Tc.onEvent(Sender);
  Tc.Free;
end;